DBACUNOULUS MEDINENSIS. 377 



many instances tending to prove that in order that a European 

 should become infected with the Guinea-worm on the coast of 

 Ajfrica, it is not necessary that he should have been on shore at all. 

 It has been quite sufl&cient for him to have exposed the bare sur- 

 face of some part of his person to the water in the native canoes 

 alongside, or, it may be, to the discharge from the sores of those 

 laboTiring under the disease. This mode of its introduction accounts 

 for the frequency with which the legs and feet are attacked by the 

 parasite in preference to other parts of the body, as it will always, 

 I beheve, be found that the men who have become so affected have 

 been in the habit of going about with bare feet, as is common 

 among sailors in warm latitudes. That the contagious material is 

 conveyed in water is also further indicated by the well-known fact 

 that in India, where it is the custom of the natives to carry water 

 in sMns on their backs, the worm makes its appearance on the 

 back and shoulders, and upper part of the body." Nothing that 

 has since been written has had the sHghtest tendency to contradict 

 the above conclusions, which, in point of fact, are essentially cor- 

 rect. It would appear, also, that the Dracunculus gains access to 

 the human body without reference to age or sex, race or country, 

 the only necessary condition being that the skin be exposed to 

 water in those localities where the Dracunculi flourish. 



Even more cogent illustrations of the truth of this general 

 statement may be gathered from a variety of sources, and especially 

 from the recorded experience of eminent medical of&cers attached 

 to our Indian armies. Those troops which have been most exposed 

 during the rainy season have subsequently exhibited a more or less 

 marked evidence of having been invaded by the Dracimculus ; and 

 as the period of incubation of the entozoon usually extends from 

 twelve to fifteen months, it necessarily happens that the disease has 

 frequently shown itself in locahties far distant from the spot where 

 the troops originally contracted the disorder. It has been said 

 that the period of incubation of the worm is not less than a year, 

 but Carter of Bombay mentions that in a school of fifty boys bath- 



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